There is a practical problem in actually banning it. Imagine a man marries a woman. What he does, could be perfectly lawful. Imagine he divorces her after a week. Divorce is regrettable, but not actually unlawful. Lather. Rince. Repeat.
He is never openly doing anything unlawful. It it is the intention with which he marries that is a bit deceptive to his bride and her family. He may not actually intend to remain married with her for more than a week. He may actually know upfront that he will divorce his bride after a week. He could enter that kind of marriage procedure simultaneously with several brides, who do not know about this.
In my impression, no matter how many, additional obstacles that you may add to the marriage procedure, there will be no way of effectively preventing a determined deceiver from doing this.
In other words, someone may marry and divorce 50 times in a row, still claiming and insisting that none of these marriages were a form of Mutah.
The problem in outlawing behaviour that merely exists of a sequence of otherwise perfectly lawful behaviour, is that you must make assumptions about the intention of this person. You can, however, never determine that with sufficient precision. Outlawing intentions is pretty much impossible, since the real intention is never visible to others.
